Speech perception in various acoustic environments: Comparison of different sound coding strategies

Objectives to compare speech perception in a quiet and noisy environment using a basic audio coding strategy (CIS) and a modern strategy (ACE) over a period of 24 months. Material and methods. The study involved 30 patients who received hearing rehabilitation in the National Medical Research Center for Otorhinolaryngology of the Federal Medico-Biological Agency in the period of 2018 2021. The inclusion criteria were: implantation in the adult age (from 18 to 45 years), speaking fluent Russian, hearing loss after speech skills formation. After initialization and programming of the speech processor, the patients underwent speech audiometry in a free sound field using syllabic and speech tables in silence and noise. The results were collected in the special MS Excel templates and subjected to statistical analysis. Results. The intelligibility of syllables in patients with CIS and ACE strategies took comparable values and grew with experience within 24 months (from 52 7.00% at the beginning of the study to 72 7.25% at the end), the greatest increase in intelligibility was noted in the first 3 months after connecting the speech processor (from 52 7.00% to 66 7.87%). Using the Greenberg speech table in silence, the groups with the CIS strategy and the ACE strategy obtained similar results with a slight advantage of the ACE strategy up to 6 months of the study. Later, a significantly higher increase in speech perception was observed in the group with the ACE strategy compared to the group with CIS. After 12 months, the perception tests showed 67 8.62% in patients with CIS strategy and 71 7.54% in patients with ACE, after 24 months the results were 68 9.12%, and 72 8.62% respectively. Under noise conditions, we observed an increase of the difference between groups starting from 6 months (41 5.33% in patients with CIS versus 43.3 7.55% with ACE), the largest difference was registered after 24 months (51 5.50% versus 57 8.25% respectively). Conclusion. When compared to the basic strategy, a modern sound coding strategy with a higher resolution can improve speech perception especially with complex speech patterns and in a noisy environment.

Long-term data of the new transcutaneous partially implantable bone conduction hearing system Osia®

Purpose The new active transcutaneous partially implantable osseointegrated system Cochlear™ Osia® System is indicated in case of conductive or mixed hearing loss (CHL/MHL) with a maximum average bone conduction hearing loss of 55 dB, or in single-sided deafness (SSD). The implant directly stimulates the bone via a piezoelectric transducer and is directed by an external sound processor. We conducted a monocentric retrospective longitudinal within-subject clinical study at our tertiary academic referral center. The aim was to investigate long-term data (2017–2021) on audiological outcomes and hearing-related quality of life for the Osia system. Methods Between 2017 and 2020, 22 adults (18: CHL/MHL; 3: SSD) were implanted with the Osia100 implant; seven received bilateral implants. As of 10/2020, the sound processor was upgraded to Osia 2. Results Mean Osia system use by 04/2021 was 30.9 ± 8.6 months (range 17–40 months). Unaided bone conduction thresholds were unchanged postoperatively. One patient had to be explanted because of prolonged wound infection. Aided hearing thresholds were significantly lower compared to the unaided thresholds preoperatively, along with a marked increase in speech recognition in quiet. Speech processor upgrade resulted in a stable benefit. Patients with CHL/MHL and SSD showed a similar improvement in self-rated hearing performance revealed by SSQ, APHAB, and HUI questionnaires. Conclusion The Osia system is a safe, effective and sustainable option for treatment of conductive and mixed hearing loss or single-sided deafness.

Noise Attenuation Effects on Speech Recognition of Cochlear Implant Users Inside Helicopters

BACKGROUND: The speech recognition levels of cochlear implant (CI) users are still incompatible with ICAO hearing requirements for civil aviation pilots testing in the noisy background condition of the helicopter cockpit. In this study, we evaluated noise attenuation effects on speech recognition in the same background condition.METHODS: The study involved the evaluation of 12 Portuguese-speaking CI users with post-lingual deafness and with a pure tone average up to 35 dB HL between 500 and 2000 Hz and up to 50 dB at 3000 Hz on at least one of the ears, and of three normal hearing pilots (controls). We performed speech recognition tests using sentences, numbers, and disyllables for all participants through the VHF radio. The assessment took place inside a helicopter with engine on, using three setups: 1) with headset without the active noise cancellation; 2) activating the noise cancellation system of the headset itself; and 3) connecting the speech processor directly to the helicopter radio system.RESULTS: The headset active noise-cancellation improved only the recognition of sentences. The direct connection system compared to the headset without anti-noise attenuation significantly improved all the recognition tests. The median for numbers was 90%, but the best score for disyllables recognition was 56%.DISCUSSION: The noise attenuation resources proposed in this study improved the CI users speech recognition when exposed to the noisy helicopter cockpit. However, speech recognition of CI users still did not meet the standards of ICAO, which requires at least 80% for understanding disyllables in the speech in noise test.Caldeira JMA, Goffi-Gomez MVS, Imamura R, Bento RF. Noise attenuation effects on speech recognition of cochlear implant users inside helicopters. Aerosp Med Hum Perform. 2021; 92(11):880-885.

The Impact of Cumulative Cochlear Implant Wear Time on Spoken Language Outcomes at Age 3 Years

Purpose The purpose of this study was to analyze the impact of cumulative hearing hour percentage (HHP) on pediatric cochlear implant users' speech and language development at age 3 years and to determine an evidence-based wear time recommendation that yields typical spoken language standard scores. Method A retrospective chart review of 40 pediatric cochlear implant recipients was completed. Children met the following criteria: prelingually deafened, implanted at age 2 years or younger, utilized a speech processor with datalogging capabilities, a minimum of 1 year of cochlear implant use, and language testing completed at approximately age 3 years. Exclusion criteria included significant inner ear malformation (i.e., common cavity) or developmental delay that would preclude spoken language development. Results Multiple regression analysis revealed that age and implantation and HHP were predictive of spoken language skills at age 3 years. Further analysis yielded wear time recommendations associated with age-appropriate spoken language based on the age at implantation. Conclusions When the goal is age-appropriate spoken language, wear time recommendations should reflect a child's current age, age at implantation, and the comparative daily sound access of age-matched normal-hearing peers. The HHP measurement can help provide that information. The minimum wear time recommendation should be set to 80% HHP with the ultimate goal of 100% HHP to give pediatric cochlear implant recipients enough access to sound and language to achieve their spoken language goals.

Word Recognition and Frequency Selectivity in Cochlear Implant Simulation: Effect of Channel Interaction

In cochlear implants (CI), spread of neural excitation may produce channel interaction. Channel interaction disturbs the spectral resolution and, among other factors, seems to impair speech recognition, especially in noise. In this study, two tests were performed with 20 adult normal-hearing (NH) subjects under different vocoded simulations. First, there was a measurement of word recognition in noise while varying the number of selected channels (4, 8, 12 or 16 maxima out of 20) and the degree of simulated channel interaction (“Low”, “Medium” and “High”). Then, there was an evaluation of spectral resolution function of the degree of simulated channel interaction, reflected by the sharpness (Q10dB) of psychophysical tuning curves (PTCs). The results showed a significant effect of the simulated channel interaction on word recognition but did not find an effect of the number of selected channels. The intelligibility decreased significantly for the highest degree of channel interaction. Similarly, the highest simulated channel interaction impaired significantly the Q10dB. Additionally, a strong intra-individual correlation between frequency selectivity and word recognition in noise was observed. Lastly, the individual changes in frequency selectivity were positively correlated with the changes in word recognition when the degree of interaction went from “Low” to “High”. To conclude, the degradation seen for the highest degree of channel interaction suggests a threshold effect on frequency selectivity and word recognition. The correlation between frequency selectivity and intelligibility in noise supports the hypothesis that PTCs Q10dB can account for word recognition in certain conditions. Moreover, the individual variations of performances observed among subjects suggest that channel interaction does not have the same effect on each individual. Finally, these results highlight the importance of taking into account subjects’ individuality and to evaluate channel interaction through the speech processor.

Reducing interaural tonotopic mismatch preserves binaural unmasking in cochlear implant simulations of single-sided deafness

Binaural unmasking, a key feature of normal binaural hearing, refers to the improved intelligibility of masked speech by adding masking noise that facilities perceived spatial separation of target and masker. A question particularly relevant for cochlear implant users with single-sided deafness (SSD-CI) is whether binaural unmasking can still be achieved if the additional masking is distorted. Adding the CI restores some aspects of binaural hearing to these listeners, although binaural unmasking remains limited. Notably, these listeners may experience a mismatch between the frequency information perceived through the CI and that perceived by their normal hearing ear. Employing acoustic simulations of SSD-CI with normal hearing listeners, the present study confirms a previous simulation study that binaural unmasking is severely limited when interaural frequency mismatch between the input frequency range and simulated place of stimulation exceeds 1-2 mm. The present study also shows that binaural unmasking is largely retained when the input frequency range is adjusted to match simulated place of stimulation, even at the expense of removing low-frequency information. This result bears implication for the mechanisms driving the type of binaural unmasking of the present study, as well as for mapping the frequency range of the CI speech processor in SSD-CI users.

Design of Low Power Speech Processor-Based Cochlear Implants Using Modified FIR Filter with Variable Frequency Mapping

Generally, cochlear implant system consists of one or more electrodes which directly activate the auditory nerve. The microphone transforms external speech processor input into stimuli for each electrode and transcutaneous the connection between the electrodes and processor. As a result, cochlear implants continue to improve the performance of speech processor. After the implantation, preservation gains importance in acoustic hearing to prevent the neural degradation from the loss of cells. Eventually, the possibility of preserving low-frequency and high-frequency hearing using modified surgical technique has been explored for hearing in cochlear implantation. The primary focus on the architecture is to reduce the major potential thread performance and power trade-off. So, frequency mapping function with modified FIR filter has been proposed. For this implementation, the values relative to the frequency range defines upper and lower stimulus limits of each electrode. The proposed FIR filter is designed with distributed arithmetic function where the reconfigurable FIR filter can change the filter input coefficients. By scaling both the frequency ranges and by assessing the deriving frequency parameters, the mapping function will be yielded. Mapping function is manipulated to rectify any mapping deviations. This results in favor of the development of frequency specific mapping function with flexible system. From the proposed results, it is evident that the speech recognition performance is improved significantly by better minimization of overall energy consumption based on effective and pipelined FFT architecture. This implementation also reduces the power and improves the accuracy by 90% and above for different frequency ranges.

Cochlear Implant Rehabilitation During Covid-19 Pandemic: A Parents’ Perspective

Aim and Objectives: The current study was undertaken to assess the effect of Coronavirus disease 2019 (COVID-19) pandemic on cochlear implant rehabilitation of children with congenital non syndromic bilateral severe to profound sensorineural hearing loss (SNHL). The objectives were to find out the psychological impact of COVID-19 on parents of children with cochlear implant habilitation, to assess the performance of children with cochlear implant habilitation through tele therapy and to analyze the problems faced by the parents to obtain the professional hearing health care services for their cochlear implanted children.Material and Methods: An online questionnaire survey was conducted amongst the parents of children who had undergone cochlear implantation (CI) consequent to congenital severe to profound SNHL. Prior to COVID-19 pandemic, these children received regular auditory verbal therapy (AVT) including visits to the Centre for audiological services (mapping and troubleshooting of the speech processor).Results: The online questionnaire survey, undertaken by a total of fifty (50) parents was analyzed. All the parents unanimously reported that COVID-19 pandemic has adversely affected access to the professional health care services for regular mapping and troubleshooting of the speech processor and thus their children’s rehabilitation. However, active involvement between the professional health care services and the parents through video consultation and tele auditory verbal therapy has definitely helped the children to a great extent.Conclusion: The present study emphasises the great challenge posed by the COVID-19 pandemic for continued rehabilitation of CI children. To overcome this situation, an innovative digital media to address such medical issues through tele medicine, tele audiology and tele therapy is warranted.

The survey of parents’ and adults recipients’ satisfaction with cochlear implantation determined by the place of residence

<b>Introduction:</b> The use of cochlear implants (CI) has been a remarkable success in reducing disabilities in patients with impaired hearing. The definition of success for those patients means improvement of hearing ability for adults, possibility to develop speech and language for children, quality of life improvement and satisfaction with the whole CI implantation procedure. <br><b>The aim:</b> To examine patient satisfaction, determined by their place of residence, with all activities in progress during CI implantation including care in subsequent years. Material and methods: The study was conducted prospectively. Online surveys were sent to 1,906 CI patients, with the response rate reaching 33%; thus 630 surveys were analyzed. Demographic data of the respondents were collected: gender, age of implantation, one- or two-sided implantation, place of residence and implanting clinic. A detailed statistical analysis of the obtained data was performed. <br><b>Results:</b> One of the problems observed was the aspect of waiting time for qualification, implantation and replacement of the speech processor. The second problem was the travel time to the CI center and that was strictly connected with the place of the residence of a patient. Patients’ satisfaction with the control visit was high for majority of them. <br><b>Conclusions:</b> This research highlighted the limitations of the current CI service delivery. Significant differences concerning the CI pathway were found for particular regions of Poland. One of the future goals for healthcare providers should be to level out the differences in access to CI services between different regions of Poland.